In an ink-jet recording head, a vibration plate constitutes part of pressure generating chambers communicating with nozzle orifices which eject ink droplets. Piezoelectric elements deform this vibration plate to pressurize ink in the pressure generating chambers, thereby causing the nozzle orifices to eject the ink droplets. There are two types of piezoelectric actuators which have been employed by this ink-jet recording head for practical use: a piezoelectric actuator of a longitudinal vibration mode which extends and contracts in an axial direction of the piezoelectric elements; and a piezoelectric actuator of a flexure vibration mode. A well-known example of the ink-jet recording head employing the actuator of the flexure vibration mode is as follows: a uniform piezoelectric material layer is formed over the entire surface of the vibration plate by deposition technology; this piezoelectric material layer is cut into pieces by use of a lithography method so that the shape thereof becomes suitable for the pressure generating chambers; and the piezoelectric elements are formed independently for the respective pressure generating chambers. Moreover, these piezoelectric elements are generally driven by a drive IC (semiconductor integrated circuit) or the like, and the drive IC is mounted on, for example, a joint plate joined with one side of a passage-forming substrate on which the pressure generating chambers are formed. This drive IC and drawn wires drawn from the respective piezoelectric elements are electrically connected by connection wires, which are formed by wire bonding (e.g., refer to Japanese Unexamined Patent Publication No. 2002-160366).
However, such an ink-jet recording head has a problem that adjacent drawn wires are short-circuited when the drawn wires and connection wires are connected. This is because widths of the drawn wires and the pitch thereof are narrowed in line with a shift toward high-density piezoelectric elements. In other words, there is a problem that the adjacent drawn wires are short-circuited by the connection wires projecting to the outside of the drawn wires since regions of the drawn wires connected to the connection wires are narrowed. In addition, there is another problem that connection strengths degrade between the connection wires and the drawn wires if connection areas between the two are extremely small. Note that these problems arise not only in the ink-jet recording head which ejects ink, but also in other liquid jet heads which eject liquid other than ink.